kentcowgill.org/blog

Hooray!

Shortly after complaining about how long my main page was taking to load, I started thinking up ways to make it go faster. As far as I could see, one option would be to try to parse the perl with perl - but just borrow all the ideas and regexes from the perl.vim vim syntax file. Easy enough - just figure out what the metacharacters in vim map to in perl, etc etc and so forth.

About a third of the way through my translation, I realized it was going to be harder than I was expecting/hoping, because there are some conventions in vim's syntax files that makes that sort of thing somewhat easy.

Plus, I wasn't even sure how good the translations were, or whether or not they'd even do anything useful:

my( $I, $i )
  = ( qr/[A-Za-z_]/, qr/[0-9A-Za-z_]/ );

my $packageRef = qr/(?:$I$i*)?(::|')$i/;

my $varPlain
  = qr/\\?(?:[@%\$]|\$#)\$*(?:
        $I$i)?(?:(?:::|')$I$i*)*\b/x;

my $functionName
  = qr/\\?&\$*(?:$I$i*)?(?:
        (?:::|')$I$i*)*\b/x;

Yuck.

I toyed with the idea of doing something with PPI, but quickly dismissed that.

I then thought I might've remembered reading something about creating some kind of "vim server" with Text::VimColor - so a quick read of that yielded nothing. But I noticed the link in SEE ALSO to Apache::VimColor, which thank goodness mentions Cache::Cache (and sibling Cache::FileCache).

What was I thinking?

So the solution was exceedingly simple:

use Cache::FileCache;

# to create a key for the cache
use Digest::MD5;

sub vimformat {
  my( $self, $text ) = @_;
  my $key = Digest::MD5::md5_hex( $text );
  my $cache = new Cache::FileCache;
  my $return = $cache->get( $key );
  if( ! defined $return ){
    # do hugely time-expensive formatting, set
    # the value of $return to desired text
    # set the cache key at the end
    $cache->set( $key, $return );
  }
  return $return;

And just like that, the page is back to being under 2 tenths of a second to create. Even with (as of this post) more than 10 hunks of syntax colored code.

Yay!